I have always suspected that the US method of converting corn into ethanol was detrimental. A new study suggests it has a net negative effect on global warming. In addition to that, we are turning food into fuel which would tend to drive up food prices. In the current situation of high...
We have a longstanding problem with low suction pressure to a set of vacuum tower bottoms pumps. I will briefly describe the service and the pumps before describing the problem.
The pumps are single stage, double suction, radial split, between bearings, API centrifugal pumps. They are rated...
I attempted to do a search for my question and was not able to find any relevant threads. I apologize if I missed any.
We are in the process of designing a replacement cooling tower. It is expected to have 6 fans, 18 feet in diameter, driven by 150 HP motors. The cooling tower manufacturer...
Three years ago, I posted a question about the use of spiral wound gaskets pressurized from OD to ID. The real issue I was exploring was a set of large barrel pumps that were chronically underperforming. I was speculating that the gasket stack between the outer head and inner casing was...
It has been about 25 years since I was heavily involved in grouting in a reciprocating compressor. At that time, our point of view was that full-bed grout was the best option for good reliability and long life. I seem to recall that we considered using epoxy chocks but decided against it. I...
I posted a question back in August about motor shaft axial shuttling in some newer pump trains with relatively large TEFC motors. Update: We have largely resolved our shuttling problem. Our motor supplier and motor repair shop establish mag center on these large TEFC motors by running them solo...
I work with a number of large industrial process gas compressors and pumps in an oil refinery. These machines have circulating lube oil systems built to API specifications. They have temperature and pressure controls with dual filters and differential pressure transmitters. Many years ago...
I will start with a disclaimer. I am a rotating machinery engineer with expertise regarding pumps and compressors. I know relatively little about motors.
We have been converting a number of motors from the original WPII configuration to TEFC. These motors tend to be in the range of 300 to 1200...
I am investigating a problem with a possible internal leak across a spiral wound gasket. After digging deeper, I found that the spiral wound gasket is oriented such that the pressure in on the outside. I realized that I could not recall ever seeing a spiral wound gasket with OD pressure. I...
I was able to repeat an experiment I saw in a You-Tube video. I dropped a very strong magnet down through a piece of copper pipe. The magnet falls very slowly through the pipe. I found this fascinating. I had limited success trying to capture this on video. I would be interested in a technical...
We have experience a number of unexplained failures of angular contact ball bearings. We are attempting to understand the issues involved. I am hoping some bearing experts and pump users can help me separate the wheat from the chaff.
A number of years ago, we found we were experiencing high...
I live in a very old house in Minnesota. The driveway was concrete and was badly cracked. I suspect that it was as old as the garage which was built in 1965. I decided to replace the old driveway. I got three quotes from three reputable contractors. In the end, I chose the highest bid. This...
I have seen a problem with two of our centrifugal pumps and am curious if anyone has seen this before or has an explanation for possible cause. First, I should provide some information about the pumps and the service. These are single-stage, overhung, centrifugal pumps that operate at 3600...
We are currently evaluating proposals for the repair of our warehouse spare pump for FCC Main Column Bottoms service in an oil refinery. We have two options that I need to compare.
The existing case is made of CA-15 (12% Chrome - ASTM A743 GR CA-15). It is badly damaged from erosion. This case...
I would like to revisit a question I asked a long time ago. I have still not been able to resolve the problem. The original post was this:
thread407-188371
I will briefly repeat my summary. We have two identical Sundyne pumps, model LMV 341. One of them has had three failures where the...
We have had three failures of a Sundyne pump model LMV-341 running in stripped sour water service. These three failure had a common pattern that we have never seen before. First, a little background may help. We have about 175 Sundyne pumps in our refinery. About 75 of those are gearbox...
There is a major push to install remote isolation valves on the suction lines to many of our pumps. This is necessary for safety. In order to try and hold costs down, the piping project managers are pushing hard to get me to accept butterfly valves for the larger sizes. These valves are...
We are having a lot of trouble with a pair of pumps used to transfer liquid CO2. The pumps are vertical in-line pumps that use a special type of gas seal designed for cryogenic service. The wear parts (bushing and wear rings) have been converted to a non-metalic material that is more tolerant...
We have been having a rash of failures in cog belt drives on fin-fans. I found an issues that I think may be the basic problem. Our supplier has been providing a mixuture of two different patterns of cog belt. The original design used cogs that were round; basically half-circles. Some new...
I have a piping designer that is proposing a piping change to a set of pumps that concerns me. The existing suction piping from the vessel is as follows:
There is an 8" nozzle off the very bottom of a fractionating column. The 8" line continues out of the skirt and tee's to go to two pumps in...
